This invention relates to an energy absorbing roadside crash barrier that operates to decelerate an impacting vehicle in a controlled manner.
Several types of roadside crash barriers have been proposed for use in decelerating vehicles. The barriers disclosed in Stechens U.S. Pat. No. 4,452,431, Gertz U.S. Pat. No. 4,352,484 and Van Schie U.S. Pat. No. 4,399,980 all employ spaced, parallel diaphragms with crushable elements interposed between the diaphragms. Another type of barrier relies on inertial forces generated when a material such as sand is accelerated in an impact. See, for example, the barriers shown in Denman U.S. Pat. No. 4,934,661 and Zucker U.S. Pat. No. 4,557,466.
A third approach is to position an energy absorbing element (a so called truck mounted attenuator) on the rear of a vehicle such as a heavy truck, and to position the vehicle in front of a work zone. Friton U.S. Pat. No. 4,635,981, Krage U.S. Pat. No. 4,711,481 and U.S. patent application Ser. No. 07/825,301 disclose various structures suitable for use for such truck mounted attenuators. In the past, these attenuators have been mounted rigidly to the back of the vehicle, and there has been a tendency for relatively light impacts to cause damage to the truck mounted attenuator that may require replacement of part or all of the attenuator.
It is an object of this invention to provide an improved roadside crash barrier which in many cases is reusable after an impact, which can be fabricated at low cost, and which allows the deceleration forces encountered by a vehicle as the barrier collapses to be selected as desired.